1. Technical Field
The invention regards a measurement system in general and particularly a system for measurement using one or more sensors.
2. Background Art
There is a need to measure temperatures across large areas, particularly temperatures where a heating cable is deployed. Even though an average temperature is within acceptable range values, local areas with harmful temperature can occur. This can typically be found where clothes or thick carpets are placed upon a floor heated by heating cables. Typical forms for damages are damages on heating cable or damages on the flooring material.
From the known art one should refer to heating cable with negative thermal coefficient, that is heating cables with a resistance that is changed relating to the temperature of the heating cable in such a way that an increase in a temperature of the heating cable with result in a reduction in the power of the heating cable. This system functions where the temperature is even, however small localised areas with increased temperature will not be compensated sufficiently, a problem that arises for instance on bathroom floors where a thick towel is placed on the floor. The temperature can then increase so far that the heating cable will be damaged or will be subjected to a reduced lifetime.
One should also refer to distributed systems where small sensors attached to the heating cable measure the temperature and communicates across a data network typically in a form of serial communication. This overcomes the above mentioned problems; on the other hand the complexity and costs are significant. First of all this means that electronics is needed at every single measurement point and also at least 2 conductors are needed for communication, typically ground and signal overlaid a power supply for each measurement point. If one measurement point is rendered inoperable, there is a risk that the communication between sensors will become partly or fully out of operations. If ground connector or signal connector is damaged all measurement points could be put out of operation.
There is therefore a need for a product that overcomes the above mentioned problems.